Mycobacterium Flashcards
What is the TST cutoff to screen for latent TB for special patient populations?
Children < 5, HIV/immunocompromised, treatment with TNF blocking agent, abnormal CXR: 5 mm
Diabetic, renal failure, IVDU: 10 mm
No risk for infection: 15 mm
What is the recommended treatments for latent TB?
Rifapentine + INH once weekly x 3 months
Rifampin daily x 4 months
Rifampin + INH daily x 3 months
INH daily for 6-9 months
How long is the ideal treatment phases for TB?
Rifampin, INH, PZA, EMB x 2 months (intensive)
RIF, INH x 4 months (continuation)
Which TB drugs require renally dosing?
PZA, EMB
What drug classes can INH impact?
INH is a CYP3A4 inhibitor
PHY, Benzodiazepine, Carbamazepine
Which HIV drug class should be avoided with Rifampin?
Protease inhibitor, use RFB
Which HIV drug should be avoided with RIF AND RFB?
Bictegravir
Is TDF or TAF recommended when combining with RIF or RFB?
TDF
When should TB drugs be discontinued due to hepatotoxicity?
3x ULN with clinical hepatitis symptoms
4x ULN with no clinical hepatitis symptoms
Restart when LFTs are <2x ULN, beginning with RIF, INH, EMB and finally PZA
How would you manage rash due to TB therapy?
Stop drugs and restart 2-3 days after resolution, RIF first, then INH, EMB and finally PZA
How would you handle TB treatment interruptions for intensive phase and continuation phase?
Intensive phase
If interruption is < 14 days, continue treatment
If interruption > 14 days, restart therapy
Continuation phase
If >80% dose given, sputum is negative, can stop
If > 80% and smear is positive, complete course
If < 80% doses are given, and all missed doses < 3 months total but no >2 consecutive months, complete therapy
If <80% doses are given, are >3 months or >2 consecutive therapy, restart therapy including intensive phase
What is the duration of continuation phase for TB per disease severity?
Pan-susceptible: 4 months Cavitary lesion: 7 months Positive culture at 8 weeks: 7 months Extrapulmonary disease: 6-10 months HIV w/ no ART: 7 months
What are the Group A, B, C drugs to treat MDR TB?
Group A
Levofloxacin or moxifloxacin
Bedaquiline
Linezolid
Group B
Clofazimine
Cycloserine
Group C
Amikacin, streptomycin, meropenem or imipenem-cilastatin
How long would treat MDR TB?
Total: 18-20 months
15-17 months after culture conversion
*If using amikacin or streptomycin for intensive phase, intensive phase needs to be 6-7 months
How long should the intensive phase and continuation phase last for MDR TB? XDR TB?
CDC recommends an intensive phase of 5-7 months after culture conversion to include (FQ, bedaquiline or linezolid, cycloserine or clofazimine)
Continuation phase to include 5 agents, total duration of 15-21 months
For XDR, total duration of 15-24 months after culture conversion
